Pathtags are a type of swag that people have made. It's like a signature item. Every pathtag of the same design has the same serial number. Hundreds may have been minted, yet all of them have the same serial number. When logged as found on pathtags.com, you will see a map of where others have found the same version of pathtag.
It is the finder's personal choice whether to keep them or send them on. Many of us collect them. I have hundreds of them I have either found or traded for. By all means log that you found it at pathtags.com no matter what you untimately do with it. That's why they have the serial number.
If you choose to use them as swag, someone else will eventually find it and may add it to their collection. They will log it as well. They may do as you did, sending it onward, or it may end up in their collection. Whatever you choose to do with it is fine. That includes contacting me and arranging to send them to me to add to my collection. *grin* (But I think you heard this option before. *smile*)